Chapter 15— Electricity Flashcards
Electricity that flows in only one direction
DC ( Direct current )
Electricity that flows one way, then another
AC ( Alternating current )
Devices that convert AC to DC
Rectifiers
The “force” with which an electric current flows
Voltage
An instrument to measure voltage
Voltmeter
The rate of the charge “flow”
Current
SI unit of voltage
Volt
SI unit of current
Ampere
Energy used per unit time
Power
SI unit of power
Watt
What does P=VI mean?
Power equals voltage times current
Companies charge electricity by watt unit? 😀
Kilowatt-hours
What materials easily conduct electricity?
Conductors
What materials do not easily conduct electricity?
Insulators
The amount a certain object hinders electron flow is what?
Resistance
What is resistance measured in?
Ohms (Ω)
What instrument is used to measure resistance?
Ohmmeter
What sort of heat is produced when electrons have to overcome “electrical friction”?
Joule heat
What is the most important factor affecting the ease of current flow?
Type O’ Material
True or false: The thinner the wire, the easier electricity can flow.
False; the thicker wire has less resistance
True or false: The longer a wire, the more resistance.
True!
True or false: If you decided one day to increase the temperature of your wire, you would have just made it harder on yourself; since now there is more resistance.
True!!!
A material that allows current to flow through it with no resistance at all or at least imperceptible amounts
Superconductor
At what temperature does a material become a superconductor?
The critical temperature
